A budget code consists of multiple segments. The Work Breakdown Structure page in Procore's Company Admin tool provides you with two (2) default segments: cost code and cost type. There is also an optional Sub Job segment, which can be enabled for use with Procore's WBS on the project level. See Enable Sub Jobs on Projects for WBS. At a minimum, all Procore budget codes must be comprised of a cost code and cost type. See What is a budget code in Procore's WBS?
A custom segment is an extension of Procore's three (3) default segments, which comprise a budget code. Custom segments are created in the Company level Admin tool by your company's Procore Administrator. They can be created alongside Procore's default segments and organised into a budget code pattern that is unique to your organisation and its project(s). Your company can create up to ten (10) custom segments to represent anything your team wants to track in Project Financials.