Next/Previous Post Navigation Within Same Sub-category

How to Navigate next and previous post to just within same child/sub category, i’m using Ocean WP theme, the theme already provide next and previous navigation, but only within top level category, i try using some plugins and still the same, only navigate within top level category, that i have a couple sub category in it, but, i need the navigation only looping in the sub category, i would really appreciate a help, Thank you guys.