A custom GPT to rule them all? How to build one?

Is it possible to create a custom GPT that can use another custom GPT to answer questions? I would like to have a general GPT that uses several specialized custom GPT to answer questions. The problem I wanna solve, is that the context window is to small to get all the knowledge in, so I wanna split the knowledge in several parts.
For example, if I have a question about tigers, the general GPT asks the Tiger GPT.
Thanks