The current Investment shows the amount invested in the stocks that you have right now. It doesn't include the amount you had invested in the stocks that you have already sold via Manage / Rebalance / Partial Exits.
Money Put In
The Money Put In (MPI) amount will give you the total amount you have invested into the smallcase from your Zerodha funds. This MPI will not change if you sell some stocks, and also In case of rebalance or manage which involves both the sell and buy order, the entire buy amount will not be added to MPI. If the difference between the buy and sell amount is excessive, only that amount will be added.
To get the Total invested amount for all the smallcases, you would need to add the Money Put In of all the smallcase together.
Please go to each smallcase > show details > Money Put In and add up those amounts. It is the total amount you have invested in smallcase from the start.
Say you bought HDFCBANK for Rs.10000 and sold it for Rs.11000 / 8000. Now your realized returns will be Rs.1000. (-2000 if loss) and Rs.10000 will be removed from your Current Investment. But this will be saved as Money Put In value. Hence you’d see your Current Investment has decreased. Hope this clarifies.
During Rebalance and Manage which involves both sell and buy, the sell amount is use to buy the new stocks.
If the sell amount > buy amount, the extra amount will be credited to your Zerodha funds.
If the buy amount > sell amount, the extra amount will be debited from Zerodha funds, and only this added amount will be added to your MPI.
Its is pretty simple. This is the today's(current) value of your investments. If you sell your investments, you will receive the amount as in Current Value.