If you DON'T use ABP's replacement Block Bullets VMT, which treats the brush as a detail type and prevents it from cutting visleaves, you can use mat_leafvis 3 to see the portals that the solid has cut. I can't find any console command that outlines Block Bullets or any other invisible tool brush like Invisible and nodraw. They are treated like solid world brushes so the above command will work to show you the visleaves cut by them, as well.
The simplest way to find a block bullets brush is to look for invisible walls you can't get past, put a sticky bomb on them and noclip into the space behind them, then see if you take damage from the sticky. If it's Invisible or a func_detail you will, but if it's Block Bullets you definitely won't (great for Deathrun maps).