Normally, the dropdown menu of the posts filter is a single selection. If you install this plug-in, dropdown menu of “single selection” will change to “multiple choice”.
For example, if you select some of the categories, you will be able to view the post belonging to any of them in the post list page.

Some features:

• Change each pull-down menu on the post list page from single selection to multiple selection.
• Sort the post data by the last modified date and time.
• Tags and author filters will be added to allow you to narrow down your search.

Support

• Japanese – https://elearn.jp/wpman/column/posts-filter-multiselect.html

Translators

• Japanese(ja) – Takenori Matsuura
• Svenska(sv_SE) – Downloadable

You can send your own language pack to me.

Please contact to me.

• https://12net.jp/ (ja)
• email to takenori.matsuura[at]gmail.com
• @tmatsuur on X(twitter).

Contributors

• Takenori Matsuura

Notice

• This plugin uses jQuery UI MultiSelect Widget under WordPress 5.5, and uses its own script for WordPress 5.5 and later.
  link: https://github.com/ehynds/jquery-ui-multiselect-widget
  Special thanks to Eric Hynds.

Credits

This plug-in is not guaranteed though the user of WordPress can freely use this plug-in free of charge regardless of the purpose.
The author must acknowledge the thing that the operation guarantee and the support in this plug-in use are not done at all beforehand.

Contact

email to takenori.matsuura[at]gmail.com
twitter @tmatsuur