Transfer between budget books

My gf and I have our individual budgets and a common “house” budget for our common bank account. Every now and then I have to top-up this common account, it would be quite helpful if there was an option to transfer money from my individual budget book to the common one.

Right now i pass lets say 100€ as expense on the first and then create another income transaction on the second. It’s not the most ideal.

Thanks for considering!