Longest path forensics

the easy way is if all of the 5 substantial completion milestones have different float values. Then you can just filter for that float value. 

The hard way is to filter for just one substantial completion milestones and then go to the precedessor window and loook for the predecessor that has is both the driving and critical boxes checked and then click on that predecessor and then click on the GOTO button for that predecessor keep doing this until you get back to the data date. 

If you want to to you can add a code for this substantial for this completion milestone and assign all of the activities to this code for that lead up to this substantial completion milestone.

you can use the same technique for the other 4 substantial completion milestones and create codes for them also 

so now if you want to see all 5 paths just filter for the 5 new codes that you just made.

please keep in mind as soon and you progress this schedule and ot make and changes to the schedule you wil have to repeat this process again becasue the paths could have changed.