Hello
There is not such option in Proe.
In purpose to help you I have prepared a list of the options you have to change the visibility of the tangent edges.
1. Views > Disp Mod > View Disp > Tan Solid, No Disp Tan, Tan Ctrln, Tan Phantom, Tan Dimmed, Tan Default, but this option takes affect all the edges.
2. Views > Disp Mod > Edge Disp > Erase line (use this option to erase the lines you don