UK listed share - how to determine if its a foreign or UK company

What are the rules for determining whether a share listed on a UK stock market e.g. LSE is considered a foreign or UK source for income tax and capital gains tax (as I understand there may be different rules). Can you provide a link to where the rules are specified? As an example BHP Ltd, has a secondary listing on the LSE, but is an Australian incorporated company, but has a registered subsidiary in the UK, its country of share register is GB, while most of its operations are outside the UK. How do you determine for dividend payments and capital gains tax whether it is considered a foreign or UK source of income?

Hi,
For the dividends received, if not paid in sterling then it is foreign income.
Thank you.