How to animate a equipable mesh along the players character ?

I want to animate some piece of cloth ( hoodie ) or armor ( breastplate ) along the players character and his animations.

I do NOT want to just attach the cloth/armor mesh to his chest, this causes it to behave strange, like its solid. Or modify the existing player character fbx file with that piece of cloth or armor... it should be changeable !

It should get transformed while the player performs actions like being idle or attacking, it should look like its part of the character mesh, like its his skin.

Lets say my player character is already rigged with bones... how would i prooced ? How would i achieve that ? And futhermore... is this called ( just for searching )...

If it helps i am using Unity of course and Blender. I have found two videos showcasing what i just explained. But without a explanation on how they did that...

https://i.gyazo.com/81c191197374c0667f93bbc65dd31bd5.mp4
https://i.gyazo.com/13b391865b3b658658b3dacaac690875.mp4

Futhermore i found this so called "Tutorial" here... but it doesnt really help me... plain text doesnt really helps one.

https://forum.unity.com/threads/tutorial-how-to-make-clothes-animate-along-with-character.475253/

I nearly havent got any experience with that topic, so i would be glad for any help i can get ! Thanks a lot

 

You could rig the clothing to the same skeleton and using the skinned mesh renderer component use the same root bone as the character's skeleton.