I don't believe there is a Nemeth symbol for two lines cut by a transversal. It probably makes sense, if you have this symbol occur frequently, to create a symbol or icon for it -- for instance edtt [braille]$ttfor shape two-transversal -- or whatever seems logical. You would define it in a tn the first time you use it, and list it on the special symbols page also. Make sure that you are not using a symbol that already has a meaning in Nemeth.
If anyone is aware of an already existing symbol for two lines cut by a transversal, please let me know.