There are four types of slots:

1. Opening point of the position sets the entry point of the position (only one)
2. Opening logic condition decide whether to open a position when the market price reaches the opening price. To open a position all presented opening logic conditions must be satisfied (you can have up to 8 of those)
3. Closing point of the position sets the exit point of the position (only one)
4. Closing logic conditions are available only when the closing point is Bar Closing (or similar). The position will be closed when at least one of these conditions is satisfied (you can have up to 8 of those)

Strategy Properties is not an indicator slot. Clicking it opens the Strategy Properties options panel.

The indicator in the Opening Point of the Position slot sets the price at which a position can be opened. If the additional signals settings allow it, this is also the price at which you will be able to add or take from the position.

When you click on this or some other strategy slot, the Indicator Properties section will open. You can change the indicator itself or any of its parameters here.

For further information read the article Opening Point of the Position.

An indicator placed in an Opening Logic Condition slot represents a logical condition.
Forex Strategy Builder sends an entry signal when market price reaches the entry price (set in Opening Point of the Position slot) and all opening logic conditions are satisfied.

For further information read the article Opening Logic Conditions.

The button Add an Opening Logic Condition allows you to add an additional Opening Logic Condition slot.
You can add up to 8 Opening Logic Conditions.

The indicator in the Closing Point of the Position slot sets the price at which a position is closed.

For further information read the article Closing Point of the Position.

If you are using the Bar Closing (or similar) indicator, you will be able to add (up to 8) Closing Logic Condition slots. In that case, provided that at least one of the indicators is fulfilled, the position will close at Close Price.

For further information read the article Closing Logic Conditions.

Using the button Add a Closing Logic Condition you can add an additional Closing Logic Condition slot. The button is active when there is appropriate indicator in the closing point slot and the number of slots is not greater than 8.