Sabir Hi,
with such a little info, it's quite hard to help if that really what you want.
I can only guess you could use signal from one node of a scene to another node which could also belong to another scene, both scenes instantiated at a given time in the game.
For instance:
some game nodes, in __process_ function or elsewhere, score is increased, then emit the signal with new score value to the score label in the UI to update it.
There is even such example in "Dodge the Creeps" tutorials if I remember well.