var doc = app.activeDocument;
var tgt = {
from: doc.paragraphStyles.item("★基本"),
to: doc.paragraphStyles.item("★見出し"),
};

var nst = tgt.from.nestedGrepStyles;
for (var i=0; i<nst.length; i++) {
tgt.to.nestedGrepStyles.add({
appliedCharacterStyle: nst[i].appliedCharacterStyle,
grepExpression: nst[i].grepExpression
});
} #dtp