You can.  Whenever I've done it, I processed time after the first group.  Then backed up the new.prt file just in case.  Then used enter time to enter the second group.  Then when you process time again, be sure to check the box the reprocess all time.  The enter time journals will show only the time you entered into each group, so you'll have two separate reports.  You will not see the previously entered time when you start the second group.  I think Sage recommends you only use "Enter Time" once, and then use "Enter Checks", but I've used "Enter Time" twice and it worked fine.  Here's an example from Knowledgebase:  https://us-kb.sage.com/portal/app/portlets/results/viewsolution.jsp?solutionid=224924750069079&page=2&position=7&q=can%20you%20enter%20time%20more%20than%20once 

You may also want to consider "Import Time" which allows you to do the work in an Excel spreadsheet, save it as a CSV, and then import the CSV file.  The only drawback I found was that keying errors aren't as easy to catch.  https://us-kb.sage.com/portal/app/portlets/results/viewsolution.jsp?solutionid=222924450019927&page=4&position=8&q=Import%20PR%20time 

You can.  Whenever I've done it, I processed time after the first group.  Then backed up the new.prt file just in case.  Then used enter time to enter the second group.  Then when you process time again, be sure to check the box the reprocess all time.  The enter time journals will show only the time you entered into each group, so you'll have two separate reports.  You will not see the previously entered time when you start the second group.  I think Sage recommends you only use "Enter Time" once, and then use "Enter Checks", but I've used "Enter Time" twice and it worked fine.  Here's an example from Knowledgebase:  https://us-kb.sage.com/portal/app/portlets/results/viewsolution.jsp?solutionid=224924750069079&page=2&position=7&q=can%20you%20enter%20time%20more%20than%20once 

You may also want to consider "Import Time" which allows you to do the work in an Excel spreadsheet, save it as a CSV, and then import the CSV file.  The only drawback I found was that keying errors aren't as easy to catch.  https://us-kb.sage.com/portal/app/portlets/results/viewsolution.jsp?solutionid=222924450019927&page=4&position=8&q=Import%20PR%20time