Right-click on the unallocated disk area and select New Simple Volume to create an additional partition.
For example, we want to create two partitions of 7 GB and 8 GB on the 15 GB USB flash device
Specify the size of free space after shrinking and click Shrink.
Right-click the partition on the USB stick and select Shrink Volume in the context menu.
Format the USB flash drive in the NTFS file system and then open the Disk Management (diskmgmt.msc) console.
Connect the USB stick to the computer’s USB port.
We will compress it and create the second (and subsequent) partitions: Suppose that a primary partition is already created on the USB stick, which occupies the entire volume of the USB media. Let’s try to create several partitions on a USB stick in Windows 10. How to Create Multiple Partitions on a USB Drive in Windows 10?
Create Multiple Partitions on a USB Flash Drive Using PowerShell.
Partition USB Drive in Windows 10 Using DiskPart.
How to Create Multiple Partitions on a USB Drive in Windows 10?.