Here’s a script that will copy GREP styles, even if they’re nested in up to 2 levels of style groups. Copy the text below to a text editor like NotePad or TextEdit, then save as a file with a “.js” ending. Copy it into the Scripts Panel folder inside the Scripts folder inside the InDesign application folder. The first 4 lines of comments explain how to use it:

//This utility will copy GREP styles into styles that are nested in up to two levels of groups i.e. Main Style Group>Headings Group>Heading 1
//Create a style at the lowest level of the Paragraph Styles i.e. NOT in a style group.
//Put all the GREP styles you wich to copy into this style.
//Type the style name between quotes in the line below. Then run the srcipt and select the styles to which you want to copy the GREP styles.
var source = ‘GREPSourceStyle’;
var theDoc = app.activeDocument;
var pStyles = theDoc.allParagraphStyles;
var pStyleStringList = [];// listbox
fillpStyleStringList();
var getpStyleIndexinpStyles = selectpStyle(pStyleStringList);//[1,2,3,4, 5]
var selectedpStylesByName = getSelectedpStyleNames(getpStyleIndexinpStyles);
l = selectedpStylesByName.length;

while(l–){setGrepStyle([selectedpStylesByName[l][0]],[selectedpStylesByName[l][1]],[selectedpStylesByName[l][2]])}

function fillpStyleStringList(){
for(i = 0 ; i < pStyles.length; i++){
if(pStyles[i].parent.parent.toString() === ‘[object ParagraphStyleGroup]’){
pStyleStringList.push(‘Group: ‘ + pStyles[i].parent.parent.name + ‘, Subgroup: ‘ + pStyles[i].parent.name + ‘, Name: ‘ + pStyles[i].name);
}else if(pStyles[i].parent.toString() === ‘[object ParagraphStyleGroup]’){
pStyleStringList.push(‘Subgroup: ‘ + pStyles[i].parent.name + ‘, Name: ‘ + pStyles[i].name);
}else{
pStyleStringList.push(‘Name: ‘ + pStyles[i].name);
}
}
}

function selectpStyle (array){
var myWindow = new Window (“dialog”, “Please select your target paragraph styles.”);
var myInputGroup = myWindow.add (“group”);
var select = myInputGroup.add (“listbox”, [0, 0, 300, 300], array, {scrolling: true, multiselect: true});
var myButtonGroup = myWindow.add (“group”);
myButtonGroup.add (“button”, undefined, “OK”);
myButtonGroup.add (“button”, undefined, “Cancel”);
if (myWindow.show() == 1){
var mySelection = select.selection;
var tmpList = [];
for(g = 0; g < mySelection.length; g++){
tmpList.push(mySelection[g].index);
}
return tmpList;
myWindow.close();
}else{
exit();
}
}

function getSelectedpStyleNames(getpStylesIndexinpStyles){
var currentTargetpStyleName;
var SelectedNameArray = new Array();
for(j = 0; j < getpStylesIndexinpStyles.length; j++){
var tempArray = new Array(2);
currentTargetpStyleName = pStyles[getpStyleIndexinpStyles[j]].name;
currentTargetpStyleSubgroup = pStyles[getpStyleIndexinpStyles[j]].parent.name;
currentTargetpStyleGroup = pStyles[getpStyleIndexinpStyles[j]].parent.parent.name;
tempArray[0] = currentTargetpStyleGroup;
tempArray[1] = currentTargetpStyleSubgroup;
tempArray[2] = currentTargetpStyleName;
SelectedNameArray[j] = tempArray;
}
return SelectedNameArray;
}

function setGrepStyle(targetGroup, targetSubgroup, targetName){
var target
error = “”;
basepStyle = theDoc.paragraphStyles.item(source);
if (!basepStyle.isValid) error = ‘Source style does not exist’;
if(targetGroup != “” && targetGroup != theDoc.name && targetGroup != app.name){
var temptarget = theDoc.paragraphStyleGroups.itemByName(targetGroup.toString());
target = temptarget.paragraphStyleGroups.itemByName(targetSubgroup.toString()).paragraphStyles.itemByName(targetName.toString());
}else if(targetSubgroup != “” && targetSubgroup != theDoc.name && targetSubgroup != app.name){
target = theDoc.paragraphStyleGroups.itemByName(targetSubgroup.toString()).paragraphStyles.itemByName(targetName.toString());
}else{
target = theDoc.paragraphStyles.itemByName(targetName.toString());
}
if (!target.isValid) error += ‘\rTarget style does not exist’;
if (error != “”){alert (error); exit()}
gs = basepStyle.nestedGrepStyles;
for (i = 0; i < gs.length; i++){
target.nestedGrepStyles.add (gs[i].properties);
}
}