There are three ways in which you can share files between virtual machines:
Create ISO images
If the files are small, the easiest and the quickest way to migrate files to a machine is to create an ISO image, then connect them to virtual machines.
Use a VMDK file
Create a new VMDK disk and attach it to the source machine. Copy all the data to it, then shutdown the source machine. Remove this disk from source and attach it to the destination machine, where you want to migrate files.
Note: VMware does not support hot remove of a VMDK. Shutdown the machine before removing a VMDK. Hot add is supported.
You cannot share the same VMDK between multiple guest operating systems because it would lead to disk corruption.
Create a new virtual machine for sharing
You can create a new virtual machine on your ESX host to act as a jump box in between the two VMs you wish to share files with. This jump box must have 2 NICs - one NIC attached to the source VM network and another NIC attached to the destination network. To share files, copy the files from the source VM to this jump box VM and then to the destination VM.
Note:If you want to make it more secure, you can have a single NIC attached to this jump box machine. Change the NIC to reflect the source or destination VM's network to copy files from and to as needed. After you are done with data migration, shutdown this machine and only power it on when you wish to migrate more data.