Here is one solution assuming the setup is "two main tracks" signaled for movement in either direction with a branchline joining the main tracks. This could be an Interlocking or a CTC scenario.
The triple head signal could also be a double headed signal with flashing red on bottom to indicate movements onto the branch.
As already stated above, these signals prescribe speed through the junction as opposed to switch position. The illustration shows how signals were arranged while I worked on the Frisco out of Cherokee yard. AT&SF typically use two headed signals to prescribe speed with the use of flashing indications to supplant a third signal head.
