Multiple switches cannot be connected to a Switch System. This has been a long standing issue in Revit. You can connect one of the switches to the system, but the Switch ID for additional switches must be entered manually.
I'm sorry what do you mean. Somebody told me that the three way switches has something to do with the tick marks on the wire. But I don't know how to get the tick marks on the wire either.
I don't think wire tick marks would have anything to do with 3-way switching. As mentioned, the switching system in Revit is pretty broken still, the best you can do is show your switching the old fashioned way, with wires.
In your Electrical Settings under Wiring, you have to specify what tick marks you want to use for hot, neutral, and ground (make sure they're loaded, Annotations->Tick Marks).
The first picture shows the wiring without tick marks.
The second picture shows the properties that I'm trying to make the wiring have tickmarks. Under tick marks shows ON.
The thrid picture shows the properties that I'm trying to make the wiring have tickmarks. Under tick marks shows CALCUATING.
The last picture shows the properties that I'm trying to make the wiring have tickmarks. Under tick marks shows OFF.
I hope this helps you to help me.
OK. So it's just a tick mark issue - it looks like they're not loaded. Go to Insert Tab » Load Family and browse to Annotations/TickMarks and select all of the files shown and click 'OK'. Then go to Manage Tab » MEP Settings » Electrical Settings. Select "Wiring" in the left panel and you will see the Tick Mark settings. Change these to the appropriate value.