I want to add only a select set of Students from a Student List to a Restricted Course - how can I do this?

The 'Import' function under the 'Students' tab within LabTutor Server does have the capacity to filter out students by one of the Columns from the Excel Spreadsheet / CSV file. To only add a select cross-section of the list, the best option is to add an extra column to your Student List, with the students broken down by Group / Subject. For example:

Here the 'Group' Column can be used to only add students in a particular Group to a Restricted Course. If I only want to add the Students grouped under 'Pre-Reg' to the 'Nursing Pre-Registration' Restricted Course, I can set the filter to only add Students whose 'Group' Column contains 'Pre-Reg':

In Step 2 of the Import process, only the Students whose 'Group' Column met the criteria will actually be Imported (or Updated) by this Import process - in this case only Students whose Group is 'Pre-Reg':

 
Note that the Students with their Group as 'Post' are not included in the Preview - this is due to them being filtered out for not meeting the Criteria set in Step 1 of the Import Process.