And+Or

Is there a way to have Derpibooru have an And and Or option available at once: Like if I want Twilight either grazing or doing horse things? Both kind of mean the same thing.  
(Please do answer the question even if my example isn’t perfect.)

As you asking about searching, or about editing tags on a post?

For searching, try this:
 
ts, (grazing || horses doing horse things)
 
Live example

@marinus18  
@JP  
Please note that the search syntax for AND OR NOT have synonyms:
 
&& = AND  
|| = OR  
! = NOT
 
Also please note that the terms AND OR NOT must be capitalized to be parsed correctly.
 
There’s more information about all of this in the Search Syntax Help Page.