By selecting specific conversion actions for your campaign, you can more granularly control which conversions show up in the "Conversions" column for each campaign.
In Google Ads campaigns, you can also override the default Google Ads conversions setting that defines which conversions are included in the client account conversions column.
Example: You sell shoes and clothing on your website and have two different conversion actions, one tracking shoe sales and another tracking clothing sales. You have several campaigns targeted at shoe lovers and other campaigns targeted at clothing shoppers. You might consider including only shoe purchases in your shoe campaigns, but this would not be recommended. It’s likely that customers who may be initially looking for shoes end up clicking an ad that leads to your website where they find a piece of clothing they like and purchase that instead or in addition to new shoes.
If you had used only the shoe purchases for this use case, then the automated bidding won’t observe and optimize against the clothing conversions from those valuable customers resulting in lower sales overall for your business. Instead, use a Target ROAS bid strategy and assign appropriate conversion values to your shoe purchases and clothing purchases according to how much they are worth to your business.
If you have several conversion actions that deliver different values to your business, instead of selecting specific conversions for each campaign, report all the actions in the "Conversions" column at the sub-manager account-level and use Target ROAS or Maximize conversion value bidding strategy with different values assigned to each action to optimize effectively.