Not enough storage space on new MacBook Pro to accept from external HD

My 2017 MacBook Pro died suddenly and was not able to open or even charge. I had worked for over 2 years with Apple support to try and fix the problem that led me to suddenly not having access to my computer . It had 1T of storage space on it that I backed up with Time Machine to an external HD. Because my old computer would no longer open or even charge, and I needed access asap, so I bought a new MacBook Pro with 512 GB storage because a MB pro with 1 T would have taken longer. The new one arrived yesterday. (I live 4 hours from the nearest Apple store). I had to transfer the data via that external hard drive plugged into a new MacBook but there was not enough space in the new one. I deselected some of the items to transfer and tried again, but still too many GBs. There was no way I could see to look into sections, eg movies or photos to selectively remove more data so that I could transfer the data and use the new computer asap. Is there a way to access the deselected data on the external HD it is stored on?