This setting affects how the information is displayed in the Git roll up tab on the Jira issue.
Do not display – This tab is not displayed on the Issue screen for all Jira projects.
Show for all projects – This tab will be displayed on the issue screen for all Jira projects.
Show for selected Jira projects – This tab will only be displayed on selected projects. Define one or more required projects into the textbox.
More on general settings
Git roll up issue tab setting (this page)