Step one is to determine what is being included in multiple asset bundles that can be included in just one.

https://docs.unity3d.com/Manual/AssetBundles-Browser.html

This tool lets you look at what is included in asset bundles, whether directly assigned or as a dependency of something else. It also indicates with a warming flag anything that is being included in multiple bundles.

Step two is then to just move all of those things into a separate asset bundles, which you can do from right inside that tool. Just select everything that has a warning flag, and drag it over to the section where it lists all asset bundles. It will ask if you want to make one bundle for each asset or one bundle for everything selected. Go with that option. Then, all of the asset bundles should not rely on that single dependency asset bundles.

Step one is to determine what is being included in multiple asset bundles that can be included in just one.

https://docs.unity3d.com/Manual/AssetBundles-Browser.html

This tool lets you look at what is included in asset bundles, whether directly assigned or as a dependency of something else. It also indicates with a warning flag anything that is being included in multiple bundles.

Step two is then to just move all of those things into a separate asset bundle, which you can do from right inside that tool. Just select everything that has a warning flag, and drag it over to the section where it lists all asset bundles. It will ask if you want to make one bundle for each asset or one bundle for everything selected. Go with the single bundle option. Then, all of the other asset bundles should now rely on that single dependency asset bundles.