Hi..There is no “ALL” value option include in LOV’s, if you wan to “ALL” value in the LOV’s you need to explicitly include in the LOV’s. By adding the custom code in the object WHERE clause.
Find the below link’s for more info.
Steps to insert "ALL" as a value in Object LOV to select all values in WebI prompt
http://scn.sap.com/docs/DOC-49751
http://scn.sap.com/thread/1201562
Sample code
SELECT DISTINCT
Customer.Country
FROM
Customer
UNION SELECT 'ALL'
FROM
Customer
how to bypass mandatory prompt screen to select * value in the list of values of the specific dimension.
http://scn.sap.com/community/semantic-layer/blog/2014/05/31/how-to-bypass-mandatory-prompts
sample code
SELECT Distinct '*' As AG_GROUP
From "TABLE”
WHERE "TABLE”.”FIELD" = "TABLE”.”FIELD"
UNION ALL
SELECT DISTINCT "Specific dimension which you need to include * value in LOV’s" AS AG_GROUP
From "TABLE”
ORDER BY AG_GROUP