You may have observed that the Campaign QTY cannot be observed in Historical Data tab in Forecast Part window after creating new campaign in forecast client.
This is ‘as designed’. The reason is that this view shows the historical data for demand planning (PERIODICAL_TRANSACTION_TAB) this tab only has the historical campaign qty’s. The future campaign qty’s is stored on the FORECAST_DAY_TAB.
The budget and Target sales plan numbers is entirely stored in PERIODICAL_TRANSACTION_TAB that’s why future values for these lines are visible in this tab. Budget and Target Sales Plan lines are not supported in other timelines than the standard period version (all historical data in DP is only stored in the standard period version resolution).
While the forecast data is stored in day resolution. Future campaigns are stored in day resolutions as is future forecast values.
So, it is recommended to use the Legacy client to see the data since here you see all the data both historical and forecast.