You might find SourceTrail as something that can do this. I code for a FOSS project and we had a FOSS project license for this a couple of years ago - however as of November 2019 SourceTrail has switched to a Gnu Public License so that it is free for all to use.
To use it, it needs to access a compilation database of your project; for a C++ project that can be obtained in passing from the
clang compiler but there are other methodologies that can be employed should you be using other compilers.
When it has got this information you can then use it's GUI to track the objects (methods, members, constants etc.) to see where they come from, what they depend on and where they are used. From personal experience I know that it can work with the Qt Creator (IDE) to direct that to the places where methods are declared and defined - and indeed since 4.8 of Creator that can generate the previously mentioned compilation database for you as part of building your Qt project.