Line 4c indicates these were qualified plans, so these two 60 day rollovers would not have been a problem. I assume you replaced any withholding to complete the rollovers. Reporting on 4c and 4d as you stated.
Second paragraph – with Notice 2020-51 you can roll the June 3rd distribution either back to the plan or more likely to an IRA. You have until 8/31 to complete that rollover, but only because the distribution would have been an RMD had 2020 RMDs not been waived. You will get 3 1099R forms, one from each plan, and all of them can be added together for lines 4c and 4d. Company 3 may not acceptance the rollback, and it might be easier to roll it to the IRA instead. The IRA will issue a 5498 reporting the total of these rollover contributions, so the IRS will know you rolled them over. Since 401k plans do not issue 5498 forms showing rollover contributions, that is another reason for rolling the June dist to an IRA. It will save you from having to make a explanatory statement with your return that you rolled a distribution to a non IRA plan.