I am not sure how do these three mashup display for you? Are they contained mashup? Or do you use naviation widget to open the other three mashup?
I did a sample for naviation mashup to transfer the timeselector data to another mashup.
1. Create the naviation mashup named s2, in this mashup, create two session parameter, and bind it to a time selector widget for start and end time.
2. Create another mashup named s1, add timeselector and naviation widget for this mashup
Please set the Navigation attribute:
3. Bind TimeSelector's StartDatTime and EndDateTime to Navigatgion.
4. Bind TimeSelector's update event to Navigation.
Should you have any further concern, please let use know.