ViewsUiBaseViewsWizard::build_filters in core/modules/views_ui/wizards/views_ui_base_views_wizard.php

Build the part of the form that allows the user to select the view's filters.

ViewsUiBaseViewsWizard::default_display_filters_user in core/modules/views_ui/wizards/views_ui_base_views_wizard.php

views_handler_relationship_groupwise_max::options_form in core/modules/views/handlers/views_handler_relationship_groupwise_max.inc

Extends the relationship's basic options, allowing the user to pick a sort and an order for it.

views_ui_add_item_form in core/modules/views_ui/views_ui.admin.inc

Form to add_item items in the views UI.

views_ui_config_item_form in core/modules/views_ui/views_ui.admin.inc

Form to config_item items in the views UI.

_date_views_fields in core/modules/date/views/date_views_fields.inc

Identify all potential date/timestamp fields.