I have some files in my project A that are synced with files of project B. The location of project B changed. How can I change the link to the project B files in project A?
I don't have RH2020, but if there's nothing in Properties, or the right-click menu, you might be able to hack it by opening the project rhpj file in a text editor.
WARNING: I haven't tried this. Back up your project before attempting it.
In a test project in RH2019, I linked a file from one of the sample projects. I closed RH and opened the project rhpj file in a text editor. There was a <link src="..."></link> tag which listed the original location (Project B) and the destination (Project A) of the linked file. Theoretically if you change that path to the new location, RH will sync from the new location.