Hi,

Please refer to the blog below to set the compute function for the field.https://www.cybrosys.com/blog/how-to-set-compute-function-for-field-using-odoo-17-studio.

Steps to Auto-Fill opening_meter_reading in Odoo Studio

Set opening_meter_reading as a Computed Field:

Open the properties of the opening_meter_reading field.

Enable the "Computed" option to make the field computed.

Define the Compute Method:

In the "Python Code" section for the opening_meter_reading field, you can add the following code:

for record in self:

          previous_record = self.search([], order='your_date_field desc', limit=1)

          if previous_record:

              record.opening_meter_reading = previous_record.closing_meter_reading

          else:

              record.opening_meter_reading = 0 # or some default value

Replace your_date_field with the actual date field used in your model

Hope it helps