Businesses operate a bit different than individuals in this sense. The tldr of it is

Investing Activities are expenditures in long-term assets (think things that are depreciating such as cars and laptops).

Financing are things you do in the form of something equitable in order to fund the business. This is like receiving a loan or paying off debt in order to finance your Operations and Investments. Typically re-purchasing their own equity is them essentially buying up their own financing so they can keep more of their dividends as they feel sustainable with their cash on hand in the foreseeable future.