How to split a large Photo Library

I would like to split a large library into two or more smaller libraries to be retained on my MacBook. I want to retain titles, editing, albums, etc. and I do not want the resulting two or more libraries to take more disk space than the one current library. I am using High Sierra 10.13.1 (and that update has ruined functionality of Photos!). Hoping Photos will perform better if my libraries are smaller (per advice from Apple Tech Support). Thanks.