Wordpress developer needed to help complete portfolio website

General information for the website: need somone that knows how to work with custom posts and loops
Kind of development: Customization of existing website
Num. of web pages/modules: 2
Description of requirements/features: I need an experienced wordpress developer to help me complete a build for a client. I have completed almost all of the build myself but a couple of areas are giving me trouble (I'm only really a front-end developer).

I need two pages finishing, One page which shows the custom post type I have created called 'gallery'. this page then has tabs which let you flick between the categories. (see image)

The part I can't do is there needs to be a condition to say 'if this category has more than X posts' show a 'show the rest' button. when this is clicked the remainder of the posts in that category appear underneath on the same page in the same tab.

I also need this then doing for the regular posts index as well (same template but obviously different loops).

Hopefully for someone that knows wordpress this shouldnt be too difficult. I can do all the styling etc, I just need the loops and the condition set up.
Specific technologies required: php
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