it is much simpler than it seems, an external event must first be created. In this event a global variable must be created, which when it is 1, as an action changes the scene to level 1, and writes the value 1.
This procedure must be done for each level by changing only the number 1, with 2 in the case of level 2, with 3 in the case of level 3 and so on …
Now, in the main menu, set “at the beginning of the scene” and put a sub-condition that verifies the existence of a group. This as an action has the reading of the group.
as under conditions of this, we have to create a scene variable, which if equal to 1, change the global variable level = 1.
This must be repeated for all levels, obviously changing the 1 with the 2 for the second level, with 3 for the third level and so on …
That’s it, much easier to do than to explain 
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