There are a few ways you can share individual documents with other users in your Logikcull project.
Comments
The easiest and fastest way is to @mention another user through Logikcull's comment feature.
Share URL
Grab the URL for a document from the document viewer by clicking “More” > “Share Document”:

Assignment
Open the document-info panel by clicking on the top-right corner
Expand the "Users" box and find the user or users you want to share the document with
Assign user(s) to the document
You can also do this in bulk using the bulk select tool from your search results.
Here's how to filter on users at the project level: