In comparison mode (see Comparison of two Trace Files) the dialog also contains a combo box that enables you to apply the chosen aggregation to the other trace file shown in the View.
Use the If match found option to find a matching function group according to the matching rules explained in Mapping of Functions and choose it. It works well for predefined groups. If no match is found, the aggregation for the other file remains unchanged.
Use the Always (Create matching FGroup) option to find a match. If a match is not found, Intel® Trace Analyzer creates a matching function group in the name space of the other file.
This operation creates a function group that mimics the hierarchical structure of the original group and contains only the functions that are present in both trace files.