When you open the Game Completion popup using the following right sidebar icon:
...then it will only show the mission for your faction, and all others will be hidden.
I'm looking to get the supporting code in for the 1.8 release (i.e. next release). In the meantime I can develop the Scenarios in preparation for release immediately after the code goes in. There should be a total of 10 new Scenarios going in:
World Classic Secret Missions - Classic, Classic*, and Medieval
World Tribes Secret Missions - Classic, Classic*, and Medieval
USA Secret Missions - Classic and Classic*
South America Secret Missions - Classic and Classic*
I'm still tossing up whether I want Medieval rules for USA and South America. I'd rather have two new eras called Golden Age (c1500-1700) and Colonial Era (c1750-1850). That will need me to get Troops ported across from the old code though, which precipitates a lot of development as I'll be overhauling it a great deal, and it will drastically affect all the game code.
After that I'll be looking at getting basic Domination Scenarios and Secret Mission Scenarios in for Aegean Sea, which is a big task as I need to create 50 new Empires each with new Icons. The Empires are drafted out in my documentation, but I've yet to create them in the system.