Count if formula for multiple columns in power query

Szagal 

As variant you may add custom column to Events with OpenWindow table in each record, expand it, add one more custom column to check if the event is in Window and group the result by events taking max value from the latest column. Thus if any TRUE exists it will be returned, otherwise FALSE.

let

    getOpenWindow = Excel.CurrentWorkbook(){[Name="OpenWindow"]}[Content],
    changeOpenWindowType = Table.TransformColumnTypes(
        getOpenWindow,
        {
            {"from", type time},
            {"to", type time}
        }),

    getEvents = Excel.CurrentWorkbook(){[Name="events"]}[Content],
    changeEventsType = Table.TransformColumnTypes(
        getEvents,
        {{"time", type time}}),

    addOpenWindow = Table.AddColumn(
        changeEventsType,
        "Custom",
        each changeOpenWindowType),
    expandWindows = Table.ExpandTableColumn(
        addOpenWindow,
        "Custom",
        {"from", "to"},
        {"from", "to"}),
    checkIfInWindow = Table.AddColumn(
        expandWindows,
        "IsIn",
        each [time] >= [from] and [time] <= [to],
        Logical.Type),
    groupBack = Table.Group(
        checkIfInWindow, {"time"},
        {
            {"inWindowTime", each List.Max([IsIn]), type logical}
        })
in
    groupBack

Result is