'Portfolio bidding' is a bidding type you create in each account and can be set to multiple campaigns. This can be created in 'Portfolio bidding tool'. By setting 'Portfolio bidding' in advance, you can easily apply auto bidding to multiple accounts.
For details on bidding settings see the following help page.
Bidding setting on Campaigns
Create Portfolio Bidding
Set Auto Bidding to Campaign or Ad Group
Create Portfolio Bidding
Steps
	
Click the [Search Ads] tab of the Campaign Management tools.
	
Click the allow on the [Tools] tab, and select 'Portfolio bidding tool' from the pulldown menu. 

Or click the [Tools] tab, and select 'Portfolio bidding tool' from the 'Tools' page.
	
On the "Auto Bidding Setting List" page, click the [Create Portfolio bidding] tab. 
	
 Select and click the Auto Bidding type to create.
	
Select and enter various required information and setting in each columns.
	
Click the [Create] button.
Set Auto Bidding to Campaign or Ad Group
You can set the created Auto Bidding setting to your campaign to apply the Auto Bidding to keywords under the campaign.
Please check the following help topics for the steps to set auto bidding on the existing campaign
Bidding setting on Campaigns
Note
The Bid Adjustment rate may be invalid depending on the created Auto Bidding type. More details can be refered on the help topics for each Auto Bidding type. About the Bid Adjustment in detail, see the following help topic
'Bid Adjustment'