A Location ID is required by Lightning Payroll for PAYG reporting (STP and End of Year). This value is also known as a PAYG Branch ID. The default value is 1, which means your company has one PAYG Reporting branch.
The ATO states that "A branch is formed where a business entity separately registers its branch to suit the structural, management and accounting arrangements of the organisation. When an entity registers a branch for GST or PAYG purposes, the entity is called the 'parent entity'."
You will need to register with the ATO for additional PAYG branches. See here for more information - https://www.ato.gov.au/Forms/Register-GST-or-PAYG-withholding-branch/