Could you upload your workbook? Also, is Booking a dimension (like ID) or measure (like number of booking)?
Can you share a workbook with sample data please.
I added the sample workbook
I can't open you workbook - I'm getting and error ("collation::resolve: Unknown collation"). I'm using 10.5.
Maybe because the data file was missing? I uploaded a new version with an included extract of data, could you try again?
It works now. I've created a calculation Booking Type:
IF COUNTD([Type])>1 THEN "Multiple Types" //check for number of booking, if more than 1 then multiple
ELSEIF min([Type])=max([Type]) THEN //if only one booking type label it
WHEN "flight" then "Flight"
WHEN "hotel" then "Hotel"
WHEN "train" then "Train" END)
I also created a chart, that will hopefully answer your question.