There is a block named "Condition" where you compare one value with another, this is basic. There are few other blocks that do this, but a little bit more complex, like those in "Indicators" category, but the idea is the same - if whatever is compared and the comparison is true - pass the block.
Whole candle... what is whole candle? For someone it can be the difference between Open and Close, for other it can be the difference between High and Low.