A Soft Object Path can be gotten from an object using the “GetPath” and “Make Soft Object Path” functions. Unfortunately getting the level path through blueprints can be a little tricky as they are not exposed very well to Blueprints.
The easiest way would be to right click on your level and level sequence in the Content Browser and choose Copy Reference. This will give you something like:
World’/Game/Maps/MyCoolCinematicLevel.MyCoolCinematicLevel’
For the soft object path you need to remove the prefix (and trailing ') like so:
Game/Maps/MyCoolCinematicLevel.MyCoolCinematicLevel
Then you can use these in the Make Soft Object Path function.
If you have a reference to your level sequence you could just use GetPath/MakeSoftObjectPath instead of hard coding it. If you need the level to be dynamic, then you will have to keep track of which level is loaded due to limitations in the Blueprint API when working with levels.