How to export computed fields

There are 3 different types of Computed fields:

Type of computed field	Formula calculates
Computed	A computed field formula calculates each time a user creates, saves, or refreshes a document. The field is not refreshed when the user opens the document, even in edit mode.
Computed when composed	A computed-when-composed field formula calculates only once: when the user first creates the document. Use this type of formula in a field to preserve information about the origin of a document, such as the creation date or original author, or to create a field whose original value never changes, such as a document sequence number.
Computed for display	A computed-for-display field formula recalculates each time a user opens or saves a document. Use this type of formula in a field to display information that is relevant only to the immediate session, such as the current time or the results of calculations that you don't need to save. The field value exists during the current session only and is not stored. You cannot display the contents of a computed-for-display field in a view.

“Computed” and “Computed when composed” are part of Notes backend document and therefore will be part of a XML metadata.

As for “Computed for display” fields, they are not part of the Notes backend and therefore will not be part of metadata XML either.

For “Computed for display” type fields to be included in metadata XML, custom metadata needs to be created.