As MK Studio say, you’ll need to use cast node, but you also can use the node «get all widget of class» which cost more (if I say nothing wrong).
If you want to cast you’ll need an object reference, they’r more than one technique to get your object reference.
example:
When you create widget (inside the blueprint, it’s doesn’t really mater if it’s level bp or simple actor or pawn) you save the output inside an object variable and reuse it later.
Master_Blueprint create Widget1 and Widget2->stock variable of both in separate variable (or array)->Widget1 ask Master_Blueprint to give variable of Widget2->then you can cast from widget1 to widget2
In my opinion you should directly set an object reference inside the widgetBP.
Let me know if it help you a little bit more with those explanation.