Hi,
By default the menu Leaves --> Configuration --> Leave Types, is visible for the users with the Group Leaves/Officer. Seems your issue is that you are not able to see the leave types right ? First what you can do is that the login as admin(or super user) and see whether you can see those records in this logins. To become super user, activate the developer mode and click the debugger button near logged in users name and click the Become Super User button from it.
If you are able to see the leave type records in the above login, the issue is with the access rights or the record rules. The model name of the leave type is hr.leave.type .
Then navigate to Settings -> Technical -> Security -> Access Rights(keep developer mode activated) and search for the records of the model hr.leave.type. ( While searching the records type the model name and rather than clicking enter, move mouse down to choose search the object). Then you will get the access rights created for the leave type model, from here check whether the Internal User Group have read access ticked, if not, grant the read access for it. Once done this, login to the user profile and check whether the issue is resolved or not.
Thanks