Custom access given to Admin dashboard

As your question is too broad and you do not specify what they should be allowed to access the answer is also broad. you can modify the role system with the “user role editor” plugin.

https://de.wordpress.org/plugins/user-role-editor/

It’s for setting specific rights for user roles like for Admin, subscriber or even shop roles in woocommerce. If the right you explicitely need is not provided you need to add it programmatically. But for the first i would try that plugin.