1 room apartment looking to swap to a flat with 2-4 rooms

I am currently living in 1 bedroom apartment in Charlottenburg. the flat is altbau has a spacious living space, renovated bathroom with shower, and a kitchen. keller is not included in the contract. it's located on the ground floor of the hinterhof however bright in the kitchen. I'm looking for an apartment within the ring area, with minimum 2 rooms. Ideally 3-4 rooms, with keller.