This Tool has been superceded by theSeparate Compiled Code for VIs and Other Files tool. Please download the new tool at the following location https://decibel.ni.com/content/docs/DOC-20926
If you want to see the block diagram you can press CTR + . when it loads.
There's a bug in this -- it does not work for files in .llb's. The search goes through files in llb's, but the VI to read the type of the file specifically says it does NOT work for files inside .llb's.
Thanks for letting me know about this bug. I've updated the other tool with a fix.