Please follow the provided template for making a new feature request, and search the forum first. If you don’t provide enough information, it isn’t possible to implement a feature request.
I’m moving this to Help.
Can you give more information? What do you mean by “embed”? For example, what would “embedding a tag” look like that doesn’t already exist by adding a tag?
“Embed notes” is already a topic in the help vault, under “Embed files”. You can already embed notes and headings inside another note.
As for embedding a search, you have the Dataview plugin.