Besides the options decribed by Abhilash, 2 other options are:
1) On-Demand subreport (one limitation of that approach is that the on-demand subreport can't contain a subreport.
2) at least one of the 3rd-party Crystal Reports viewers (see list at http://kenhamady.com/bookmarks.html) supports triggering viewing of another Crystal report by double-clicking inside a currently viewed report (including passing parameters, login, etc.).