Hide Alfresco Share Repository Browser button

To hide the repository link from non-admin users

open this file:

/opt/alfresco/tomcat/webapps/share/WEB-INF/classes/alfresco/share-config.xml

find this line within the <header> tags

<item type="link" id="repository" condition="conditionRepositoryRootNode">/repository</item>

Change it to:

<item type="link" id="repository" permission="admin" condition="conditionRepositoryRootNode">/repository</item>

Reload Alfresco. Now only admin users will see that link.
Note that the url will still be accessible, this will only hide the link button.