Hi,

You can use position="move" to the field from one position to another. Suppose if you need to move the field mobile, after a field phone, then you can achieve as follows:

field name="phone" position="after"

field name="mobile" position="move"

See more in: Change Position Of Field, Page or Group Using Move Attribute

Thanks

Try this way:
record id="view_crm_lead_form_inherit" model="" rel="ugc">ir.ui.view">
field name="name">CRM Lead Custom Field
field name="model">crm.lead
field name="type">form
field name="inherit_id" ref="crm.crm_lead_view_form"/>
field name="arch" type="xml">
xpath expr="//group[@name='lead_detail']" position="inside">
field name="phone" position="after">
field name="mobile" widget="phone" string="Mobile"/>
/field>
/xpath>
xpath expr="//group[@name='opportunity_partner']" position="replace"/>
/field>
/record>

In the above code, we use the xpath expression to target the main group with the name 'lead_detail'. Within this group, we use the position="after" attribute to position the 'Mobile' field after the 'Phone' field.

Additionally, we use another xpath expression to replace the entire group with the name 'opportunity_partner', effectively removing it from the view.

Make sure to adjust the group names ('lead_detail' and 'opportunity_partner') in the code snippet to match the actual group names used in your CRM Lead form view.

After applying these changes and upgrading your custom module, the 'Mobile' field should appear below the 'Phone' field in the main section of the CRM Lead form view, and it will no longer be present in the 'Extra Info' tab.